Valve-gear.



No. 659,750. Patented flct. l6, I900.

L. A. LANG.

VALVE GEAR.

(Application filed. Jan. 25, IQOQ.)

(No Nodal.)

Witnesses: Inventor Attorney UNHED STATES PATENT Futon.

LINCOLN A. LANG, OF YULE, NORTH DAKOTA, ASSIGNOR TO THE LANG RADIAL VALVE GEAR COMPANY, OF ST. PAUL, MINNESOTA.

VALVE-GEAR.

SPECIFICATION forming part of Letters Patent N 0. 659,750, dated October 1 6, 1900.

Application filed January 25. 1900. Serial No. 2,749. (No model.)

To all whom it may concern:

Be it known that I, LINCOLN A. LANG, acitizen of the United States, residing at Yule, Billings county, North Dakota, (post-office address, St. Paul, Minnesota,)haveinvented certain new and useful Improvements in Valve- Gears, (Case F,) of which the following is a specification.

Reference is hereby made to the following United States Letters Patent granted upon application by me for improvements in valvegearsviz., No. 607,058, dated July 12, 1898; No. 62l,828,dated March 28, 1899;No. 621,829, ated March 28, 1899; No. 637,345, dated November 21, 1899, and No. 637,346, dated November 21, 1899.

The presentinvention relates to an improvement applicable to valve-gears of the type set forth in the above-mentioned patents, and the invention will be readily understood from the following description, taken in connection with the accompanying drawings, in which-- Figure 1 is a side elevation of a valve-gear of the type set forth in the above-mentioned patents, hut embodying an exemplification of my present improvement; and Fig. 2 is an elevation of the same viewed ina direction at right angles of Fig. 1 from the left, shackle 16 appearing in vertical section.

In the drawings, 1 indicates the engineshaft; 2, the eccentric; 3, the eccentric-strap; 4, a pivot, to be considered for the present as a fixed pivot; 5, a bell-crank rocking on pivot 4; 6, a pivot uniting the long arm of the bellcrank to the eccentric-strap; '7, the link of the valve-gear; 8, a pivot uniting the short arm of the bell-crank to the link at about its midpoint; 9, a connecting-bar having one end connected with the eccentric-strap and the other end connected with the outer extremity of the link; 10, the pivot uniting bar 9 to the link; 11, the pivot uniting bar 9 to the eccentric-strap; 12, the link-block, adjustable along the link; 13, the radius-rod, pivoted to the link-block and going to the valve connections, and 14 the bridle-rod, by means of which the radius-rod and link-block are shifted in the link.

The parts thus far referred to will be recognized as constituting a valve-gear of the Lang type as set forth in the patents heretofore referred to and having the same mode of operation, the rotation of the eccentric serving, through bar 9, to oscillate the link upon pivot 8 and also serving, through bellcrank 5, to bodily move the link to and from the shaft, there resulting a reversible valvegear having but a single eccentric and possessing superior functional capacities.

Pivot 4, on which bell-crank 5 rocks, is to be viewed as a fixed pivot having a certain relationship to the shaft and other parts, and it will be obvious that an improper disturbance of the relationship of pivot 4 to the shaft may disturb the functional accuracy of the valve motion, which functional disturbance, while it might not be serious, becomes specially worthy of consideration in a valve-gear possessing the high measures of economical capacity found in the Lang gear.

Fig. 1 as drawn illustrates a gear for a vertical engine and shows the gear as applied in practice to marine engines. Pivot 4 being a fixed pivot some suitable support must be found for it, and such support has generally been founded upon one of the columns orsome other part of the framing of the engine or upon a rigid standard projecting upwardly from the bed-plate. Let 15 indicate any fixed part of the engine-frame and let it be assu med that this part 15 rigidly supports fixed pivot 4. Under these assumed conditions everything will be quite satisfactory; but in marine engines engaged in long runs the main shaft will become vertically loose in its bearings and susceptible of a rising-and-falling motion therein at each turn of the engine to an extent of as much as an eighth of an inch in some cases. This vertical disturbance of the position of the center of the shaft will reflect upon the accuracy of the valve motion to some extent, and it is desirable to avoid it. I therefore cut pivot 4 loose from the engineframe and mount it on a radial stretcher 18, having one end encircling the shaft. The result is that any rising-and-falling motion of the shaft produces an equivalent rising-andfalling motion of pivot 4, thus compensating for the disturbance in the position of the shaft. Pivot 4 having thus been cut loose from the en gine-framin g would tend to swing upon the shaft. I prevent this by introductoo ing restraining-link 16, having its outer end pivoted to some fixed part of the engine structure. This link may be'light, its only d'uty being to restrain the revolution of pivot 4 as the shaft turns, the link forming a guide for pivot 4 as it is moved vertically by the action of the shaft with stretcher 18. 'lheswinging of link 16 obviously causes pivot 4 as itrisesand falls to move through the arc of a circle, such departure from a straight line of motion being quite immaterial. In the case illustrated the inner pivot of link 16, connecting it with stretcher 18, coincides with pivot 4 of the bell-crank; but such coincidence-is notat all essential, the position of the pivot uniting the outer end of link 16 to stretcher 18 takingsuch position relative to pivot 4 of the bell-crank as-tlie exigencies of the valve-gear adaptation may call for. As link 16 is designed to furnish merely a restraint against revolution of stretcher 18, a full equivalent may obviously be found in other forms of restraining-guides connectingstretcher 18 with some fixed part of the engine structure. In Fig. 1 I have illustrated in dotted lines an obvious substitute for the link 16, the same con.- sisting of apivot 19 in a slotted guide connecting an extension 20 of stretcher 18 with the engine-framing.

Fig. 1 has thus far been assumed as illustrating the application of the Lang gear to a vertical engine. is uppermost, the valve-gear of a horizontal engine thus being illustrated. Assume it to he a locomotive-engine and thatlshaft 1 is capable of considerable rising-and-falling. motion with reference to part 15, as exemplified in the spring-mounted axle-bearings of a lo.- comotive. In one of the patents above referred to, No. 621,829, the effect of this motion of the axle upon the valve movement was considered and provided for by mountin g pivot 4 on an eccentric having'connection.

with the spring-mounted axle-box, so. thatthe rising and falling of the box turned the eccentric and gave a compensating adjustment to pivot 4. Fig. 1 has heretofore been considered as compensating for the vertical move.-

ment of shaft 1 in a vertical engine, and. at.

first glance it might appear that the merit of stretcher 18 was limited to. cases in which. it was desired to compensate for errors due to the motion of the shaft in the direction.

of the motion of the valve and that in. the case of a locomotive, where the shaft has a very considerable degree of. motion in. a direction at right angles to the line of valve motion,the merits of stretcher 18 would dis- Now turn Fig. 1 till part 15.

with the. link.

appear; but upon analysis it would be found that: stretcher 18 is capable of fully compensating for the otherwise disturbing motions of the shaft in horizontal engines or locomotives as fully as the system of Patent No.

621,829 and by mechanism decidedly preferable in view of thefactthat the present mechkanismsis independentof the wear of the shaft in its boxes and at the same time avoids imposing the thrusts of thelvalve-gear upon the "framing; Still having Fig. 1 upon its side, to

illustrate the locomotive example, assume shaft 1 as moving upwardly. The eifect is, obviously, tomove' pivot 4 tothe right, and ;when shaft -1. movesldownwardly then pivot 1 4 will he swung to the left. It follows that any motion of shaftlluinany direction whatjever relative to the fixedi parts of theengine structure will cause certain movements of pivot4and of all. parts ofstretcher l Given stretcher 18, with. itsrmovementsdue to the disturbing movements ot fthe shaft, there may be located upon the stretcher a point for pivot 14 in perfect compensationfor the movements of the. shaft, the point of location for pivot 4 ,upon the stretcher. being; dependent largely upon the general angular relationship of radiusrrod 13 to. stretcher/18.

Itis to benoticed' that stretcher 18 meets the direct thrusts; of the valve-gear motion,

there being imposed upon the. framing only such strain as is incident to therevolution of pivot 4 about. the shaft.

In Fig. 2 stretcher 18 is illustrated as formed of duplicate members straddling the eccentric a similar construction beingcarried. out

in bell-crank 5, this double-member system being, obviously, apreferable one inthe case of large engines.

I claim as my invention- Ina valve-gear, the combination, substantially as set forth, of a shaft, an eccentric thereon, arodless eccentric-strap carryinga pair ofpivots, a stretcher engaging theshaft,

a guide for the outer. endof the stretcher, a pivotcarried by the stretcher, a. bell-crank lever mountedonsaid pi-votand capable of "pivotal motion. only with reference to said stretcher andhaving, one of its arms engagling. one. of the pivots of. the. eccentric-strap, a.

link. pivoted to the. "other extremity of said "bell-crank lever, andia connecting-bar con- IIO 

